IDENTIFICATION OF AQUAPORIN 7 GENE POLYMORPHISM AND IN-VIVO FERTILITY OF EGYPTIAN BUFFALO BULLS

This work aimed to investigate the genetic polymorphism of Aquaporin 7 (AQP7) gene and its association with the in-vivo fertility of Egyptian buffalo bulls. A total of 188 fresh semen ejaculates were collected from 47 buffalo bulls and subjected to semen evaluation. The bulls were grouped according to in-vivo fertility relying on sire conception rate (SCR) into high (SCR>50%, n=41) and low (SCR<50%, n=6) fertile bulls. DNA was extracted from semen and a 200 bp fragment of the AQP7 gene was amplified by PCR. The genetic polymorphism of AQP7 gene was detected by restriction fragment length polymorphism, the single strand conformation polymorphism and the nucleotide sequencing. The results revealed that SCR was significantly (p<0.001) increased in high (71.4±1.3) than low (44.7±2.8) fertile bulls while the ejaculate volume, individual motility%, lives sperm%, sperm concentration and sperm abnormalities showed a non-significant difference in both groups. The AQP7 gene showed no genetic variation in all bulls. The alignment of the resultant sequence with buffalo AQP7 gene sequence (ID: XM_006066699.2) showed 100% identity (122/122), however, deletion of A49 was discovered when the sequence was aligned with ID: XM_006066700.2 of buffalo in GenBank. In conclusion, the sire conception rate is not associated with any genetic variation in Aquaporin 7 gene. The Aquaporin 7 gene could be a highly conserved sequence in Egyptian buffalo bulls. Future research on large herd populations in different regions of AQP7 gene is required for evaluating the AQP7 gene polymorphism and its association with the fertility of Egyptian buffalo bulls.